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101.
Twenty children, ten 2-year-olds and ten 3-year-olds, participated in an AB procedure. In the baseline phase, each child was trained the same four matching relations to criterion under intermittent reinforcement. During the subsequent imitation test, the experimenter modeled a total of 20 target gestures (six trials each) interspersed with intermittently reinforced baseline trials. In each session, target gestures were selected in a pre-randomized sequence from: Set 1--ear touches; Set 2--shoulder touches; Set 3--midarm touches; and Set 4--wrist touches; subjects' responses to targets were not reinforced. In each target set, half the gestures featured in nursery matching games and were termed common targets whereas the remainder, which were topographically similar but did not feature in the games, served as uncommon targets. The children produced significantly more matching responses to common target models than to uncommon ones. Common responses were also produced as mismatches to uncommon target models more often than vice versa. Response accuracy did not improve over trials, suggesting that \"parity\" did not serve as a conditioned reinforcer. All children showed a strong bias for \"mirroring\"--responding in the same hemispace as the modeler. The 2-year-olds produced more matching errors than the 3-year-olds and most children showed a bias for responding with their right hands. The strong effects of training environment (nursery matching games) are consistent with a Skinnerian account, but not a cognitive goal theory account, of imitation in young children. 相似文献
102.
One assumption of the matching approach to choice is that different independent variables control choice independently of each other. We tested this assumption for reinforcer rate and magnitude in an extensive parametric experiment. Five pigeons responded for food reinforcement on switching-key concurrent variable-interval variable-interval schedules. Across conditions, the ratios of reinforcer rates and of reinforcer magnitudes on the two alternatives were both manipulated. Control by each independent variable, as measured by generalized-matching sensitivity, changed significantly with the ratio of the other independent variable. Analyses taking the model-comparison approach, which weighs improvement in goodness-of-fit against increasing number of free parameters, were inconclusive. These analyses compared a model assuming constant sensitivity to magnitude across all reinforcer-rate ratios with two alternative models. One of those alternatives allowed sensitivity to magnitude to vary freely across reinforcer-rate ratios, and was less efficient than the common-sensitivity model for all pigeons, according to the Schwarz-Bayes information criterion. The second alternative model constrained sensitivity to magnitude to be equal for pairs of reinforcer-rate ratios that deviated from unity by proportionately equal amounts but in opposite directions. This model was more efficient than the common-magnitude-sensitivity model for 2 of the pigeons, but not for the other 3. An analysis of variance, carried out independently of the generalized-matching analysis, also showed a significant interaction between the effects of reinforcer rate and reinforcer magnitude on choice. On balance, these results suggest that the assumption of independence inherent in the matching approach cannot be maintained. Relative reinforcer rates and magnitudes do not control choice independently. 相似文献
103.
Mihela Erjavec Victoria E. Lovett Pauline J. Horne 《Journal of the experimental analysis of behavior》2009,91(3):355-376
The determinants of generalized imitation of manual gestures were investigated in 1‐ to 2‐year‐old infants. Eleven infants were first trained eight baseline matching relations; then, four novel gestures that the infants did not match in probe trials were selected as target behaviors. Next, in a generalized imitation test in which matching responses to baseline models were intermittently reinforced, but matching responses to target models were not eligible for reinforcement, the infants matched baseline models but not the majority of their target behaviors. To ensure their failure to match the target behaviors was not due to motor constraints, the infants were trained, in a multiple‐baseline procedure, to produce the target responses under stimulus control that did not include an antecedent model of the target behavior. There was no evidence of generalized imitation in subsequent tests. When the infants were next trained to match each target behavior to criterion (tested in extinction) in a multiple‐baseline‐across‐behaviors procedure, only 2 infants continued to match all their targets in subsequent tests; the remaining infants matched only some of them. Seven infants were next given mixed matching training with the target behaviors to criterion (tested in extinction); they subsequently matched these targets without reinforcement when interspersed with trials on which matching responses to baseline models were intermittently reinforced. In repeat tests, administered at 3‐week intervals, these 7 children (and 2 that did not take part in mixed matching training) continued to match most of their target behaviors. The results support a trained matching account, but provide no evidence of generalized imitation, in 1‐ to 2‐year‐old infants. 相似文献
104.
John F. Haught 《Zygon》2009,44(4):921-931
Evolutionary biology contributes much to our present understanding of life, and it promises also to deepen our understanding of human intelligence, ethics, and even religion. For some scientific thinkers, however, Darwin's science seems so impressive that it now supplants theology altogether by providing the ultimate explanation of all manifestations of life, not only biologically but also metaphysically. By focusing on human intelligence as an emergent aspect of nature this essay examines the question of whether theology can still have an explanatory role to play alongside biology in attempts to understand mind. 相似文献
105.
MacDonall JS 《Journal of the experimental analysis of behavior》2005,84(2):167-183
Contingencies of reinforcement specify how reinforcers are earned and how they are obtained. Ratio contingencies specify the number of responses that earn a reinforcer, and the response satisfying the ratio requirement obtains the earned reinforcer. Simple interval schedules specify that a certain time earns a reinforcer, which is obtained by the first response after the interval. The earning of reinforcers has been overlooked, perhaps because simple schedules confound the rates of earning reinforcers with the rates of obtaining reinforcers. In concurrent variable-interval schedules, however, spending time at one alternative earns reinforcers not only at that alternative, but at the other alternative as well. Reinforcers earned for delivery at the other alternative are obtained after changing over. Thus the rates of earning reinforcers are not confounded with the rate of obtaining reinforcers, but the rates of earning reinforcers are the same at both alternatives, which masks their possibly differing effects on preference. Two experiments examined the separate effects of earning reinforcers and of obtaining reinforcers on preference by using concurrent interval schedules composed of two pairs of stay and switch schedules (MacDonall, 2000). In both experiments, the generalized matching law, which is based on rates of obtaining reinforcers, described responding only when rates of earning reinforcers were the same at each alternative. An equation that included both the ratio of the rates of obtaining reinforcers and the ratio of the rates of earning reinforcers described the results from all conditions from each experiment. 相似文献
106.
Six pigeons were trained in experimental sessions that arranged six or seven components with various concurrent-schedule reinforcer ratios associated with each. The order of the components was determined randomly without replacement. Components lasted until the pigeons had received 10 reinforcers, and were separated by 10-s blackout periods. The component reinforcer ratios arranged in most conditions were 27:1, 9:1, 3:1, 1:1, 1:3, 1:9 and 1:27; in others, there were only six components, three of 27:1 and three of 1:27. In some conditions, each reinforcement ratio was signaled by a different red-yellow flash frequency, with the frequency perfectly correlated with the reinforcer ratio. Additionally, a changeover delay was arranged in some conditions, and no changeover delay in others. When component reinforcer ratios were signaled, sensitivity to reinforcement values increased from around 0.40 before the first reinforcer in a component to around 0.80 before the 10th reinforcer. When reinforcer ratios were not signaled, sensitivities typically increased from zero to around 0.40. Sensitivity to reinforcement was around 0.20 lower in no-changeover-delay conditions than in changeover-delay conditions, but increased in the former after exposure to changeover delays. Local analyses showed that preference was extreme towards the reinforced alternative for the first 25 s after reinforcement in changeover-delay conditions regardless of whether components were signaled or not. In no-changeover-delay conditions, preference following reinforcers was either absent, or, following exposure to changeover delays, small. Reinforcers have both local and long-term effects on preference. The former, but not the latter, is strongly affected by the presence of a changeover delay. Stimulus control may be more closely associated with longer-term, more molar, reinforcer effects. 相似文献
107.
Six pigeons were trained in a procedure in which sessions included seven unsignaled components, each offering two pecking keys, and each providing a potentially different reinforcer ratio between the two keys. Across conditions, various combinations of reinforcer ratios and reinforcer-magnitude ratios were used to create unequal reinforcer distributions between the two alternatives when averaged across a session. The results extended previous research using the same basic procedure that had included only reinforcer distributions symmetrical around 1:1. Data analyses suggested that the variables controlling choice operated at a number of levels: First, individual reinforcers had local effects on choice; second, sequences of successive reinforcers obtained at the same alternative (continuations) had cumulative effects; and, third, when these sequences themselves occurred with greater frequency, their effects further cumulated. A reinforcer obtained at the other alternative following a sequence of continuations (a discontinuation) had a large effect and apparently reset choice to levels approximating the sessional reinforcer ratio. 相似文献
108.
Six pigeons were trained on concurrent variable-interval schedules. Sessions consisted of seven components, each lasting 10 reinforcers, with the conditions of reinforcement differing between components. The component sequence was randomly selected without replacement. In Experiment 1, the concurrent-schedule reinforcer ratios in components were all equal to 1.0, but across components reinforcer-magnitude ratios varied from 1:7 through 7:1. Three different overall reinforcer rates were arranged across conditions. In Experiment 2, the reinforcer-rate ratios varied across components from 27:1 to 1:27, and the reinforcer-magnitude ratios for each alternative were changed across conditions from 1:7 to 7:1. The results of Experiment 1 replicated the results for changing reinforcer-rate ratios across components reported by Davison and Baum (2000, 2002): Sensitivity to reinforcer-magnitude ratios increased with increasing numbers of reinforcers in components. Sensitivity to magnitude ratio, however, fell short of sensitivity to reinforcer-rate ratio. The degree of carryover from component to component depended on the reinforcer rate. Larger reinforcers produced larger and longer postreinforcer preference pulses than did smaller reinforcers. Similar results were found in Experiment 2, except that sensitivity to reinforcer magnitude was considerably higher and was greater for magnitudes that differed more from one another. Visit durations following reinforcers measured either as number of responses emitted or time spent responding before a changeover were longer following larger than following smaller reinforcers, and were longer following sequences of same reinforcers than following other sequences. The results add to the growing body of research that informs model building at local levels. 相似文献
109.
Five pigeons were trained on concurrent variable-interval schedules in a switching-key procedure. The overall rate of reinforcement was constant in all conditions, and the ratios of reinforcers obtainable on the two alternatives were varied over seven levels. Each condition remained in effect for 65 sessions, and the last 50 sessions of data from each condition were analyzed. The most recently obtained reinforcer had the largest effect on current preference, but each of the eight previously obtained reinforcers had a small measurable effect. These effects were larger when the reinforcer ratio was more extreme. A longer term effect of reinforcement was also evident, which changed as a function of the reinforcer ratio arranged. More local analyses showed regularities at a reinforcer-by-reinforcer level and large transient movements in preference toward the just-reinforced alternative immediately following reinforcers, followed by a return to stable levels that were related to the reinforcer ratio in effect. The present data suggest that the variables that control choice have both short- and long-term effects and that the short-term effects increased when the reinforcer ratios arranged were more extreme. 相似文献
110.
Four pigeons were trained on eight or nine pairs of independent concurrent variable-interval schedules. The range of reinforcement ratios included extreme ratios (up to 532 to 1). Large samples of stable performance were gathered. Contrary to the findings of Davison and Jones (1995), the generalized matching law described choice more accurately than a contingency-discriminability model. Taking small samples (5 to 10 sessions) and applying a more liberal stability criterion used by Davison and Jones only increased the unsystematic variance in the data and in estimates of generalized-matching-law sensitivity. Because changing to dependent scheduling and inserting a changeover delay had no systematic effect, the deviations from generalized matching reported by Davison and Jones probably arose from imperfectly discriminated stimuli. Analysis of visits revealed that visits to the nonpreferred alternative were brief and approximately constant. When choice between the preferred (rich) and nonpreferred (lean) alternatives, regardless of position, was analyzed according to the generalized matching law, sensitivities approximated 1.0, with bias in favor of the lean alternative. This bias, which arose from an excessive frequency of visits to the lean alternative, explains undermatching as the result of fitting one line to a choice relation that consists of two displaced lines, both with a slope of 1.0. The pattern of deviation from the generalized matching line confirmed this account. The findings suggest an alternative analysis of choice that focuses on probability of visiting the lean alternative as the dependent variable. This probability was directly proportional to ratio of reinforcement. Matching, undermatching, and overmatching may all be explained by a view of concurrent performance based on foraging theory, in which responding occurs primarily at the rich alternative and is occasionally interrupted by brief visits to the lean alternative. 相似文献